The attachment of a strand of material, cord, or wire to one or more pieces of material presents challenges to today's high speed manufacturing processes. The tampon industry is an example. In the tampon industry, the rate at which the products are produced require that a high speed manufacturing process be employed.
Current tampon designs employ a withdrawal string, usually a cotton cord, to allow the user to remove the product after use. The cord must be firmly attached to the tampon pad, and must not shear the product or leave material behind upon withdrawal. Secure attachment or engagement of the withdrawal string to or around the tampon is of high importance so that there is no inadvertent detachment of the withdrawal string from the tampon while attempting to remove the tampon from the body—which would leave no easy means for removing the tampon from the body and may require the assistance of medical personnel.
The intent of a withdrawal string is that a portion or end of the withdrawal string remain outside the body for easy grasping while another end of the withdrawal string is secured to the tampon. For digital tampons and tampons used in tampon applicators, a looped withdrawal cord may be used. The withdrawal cord is looped around the tampon pledget and a portion of the loop remains outside the body. This means that instead of one, there are often two cord segments outside the body which then pass by the labia, through the introitus and into the vaginal cavity where they are engaged with the tampon.
One current method for attaching a cord to a pad involves sewing the cord to the pad, although this technique has a variety of disadvantages. The piercing of a cord by the thread actually weakens the cord, thereby requiring a thicker cord to meet any strength specifications. The use of thread to attach a cord to a pad introduces the possibility of thread breakage or jamming of the sewing apparatus. Current high speed industrial sewing machines operate at rates that are typically insufficient to feed a high speed production line. As a result, multiple sewing stations are required and their respective outputs must be merged to feed a single production line. Such multiple stations operating near their maximum rated speed, as well as the merging mechanism, increase the possibility and frequency of mechanical failures, jams, etc. Further, the reciprocating motion of traditional sewing machine movement, combined with the very thin and flexible handling qualities of thread, further increase the likelihood of jams, or mechanical failure.
Another method of attaching a cord to a pad involves punching of a cord once through the pad, and entanglement of the cord about the pad, i.e. with a knot or other restraining mechanism. Punching a cord once through a pad suffers from a lack of redundancy of attachment. Should the cord fail to puncture the pad, the needle fail to feed the cord properly, or the pad is misaligned, the cord will not be attached to the pad. Also, the force on the cord during the use of the product assembly is undesirably concentrated at the single point where the cord is attached to the pad. Cord entanglement does not offer the mechanical strength or integrity offered by a cord that is firmly attached to the pad since the cord can slip off. Simply tying a string to a pad in such a fashion creates a product which is prone to failure. Accordingly, a need exists for a cord attachment mechanism that is fast enough to support a subsequent high speed production line and which meets the reliability requirements of its users.
This application is directed to attaching a strand of material, cord or wire to one or more pieces of material and is particularly directed to an improved arrangement for the attachment of the string to the tampon pledget which provides easier facilitation of introducing the tampon into the body cavity and/or removal of the tampon from the body cavity.